FanMist troubleshooting by symptom

Record the symptom before choosing a part

Note the pump model, indicator lights, gauge reading and whether the problem affects one nozzle, one fan or the whole system. Also note whether it happens during startup, normal operation or shutdown. That information helps narrow the cause.

Before inspection or repair, follow the IHC guide: lock out electrical power, depressurize the system and verify zero pressure. Electrical tests and repairs belong with qualified maintenance personnel. Stop operating a pump with unusual noise, vibration, leaks, overheating or unstable pressure.

Red FAULT light or low pressure

The troubleshooting guide describes a pressure-proving sequence that expects 550 psi within 25 seconds. A fault can come from insufficient water supply, a restricted filter, leaks or the pressure-switch signal. The light alone does not identify a failed switch.

Start with the documented checks for the inlet supply, pre-filter and high-pressure safety switch. Give IHC the gauge reading and the point in the operating cycle when the fault occurs. See pages 3–5 of Troubleshooting by Part.

Nozzles drip after shutdown

The guide identifies incomplete depressurization as one possible cause. The electric drain valve needs to open, and the drain path must remain clear. A nozzle’s internal anti-drip parts can also be affected by deposits or damage.

Distinguish dripping after shutdown from an irregular spray while running. They lead to different checks. See the electric drain valve reference and pages 5 and 7 of the troubleshooting guide.

One nozzle or one fan has no mist

A single inactive nozzle can have a blocked orifice or internal filter. If an entire ring is affected, the supply path and ball valve are also relevant. An uneven spray can indicate partial blockage or a nozzle that does not match the intended size.

After isolating the equipment, use the nozzle and mist-ring procedures in the source document. Match replacement parts by number and specification. See pages 6–7 of the troubleshooting guide.

Wet spots or humidity below the set point

Wet spots can be associated with oversized nozzles or fans that are not running correctly. Fan operation, sequencing, nozzle selection and a clear evaporation path need to be considered together.

If the room does not reach its humidity target, review actual air exchange, total moisture output, sensor location and fan placement. An increase in exhaust or makeup air can change the required load even when the equipment has not changed. See page 7 of the troubleshooting guide and the load-calculation article.

Send the useful details with your request

Include the pump-station model, affected part numbers, the symptom, any displayed fault, the pressure reading and when the issue began. IHC can then direct you to the appropriate guide or replacement component.

• One nozzle, one ring or the entire system?
• Startup, running or shutdown?
• Recent filter, nozzle, water-treatment or building-airflow changes?
• Visible leaks, unusual sound or vibration?

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